(ĭ-nō'sĭ-tôl', -tōl', ī-nō'-) Any of nine isomeric alcohols, especially one found in plant and animal tissue and classified as a member of the vitamin B complex. Inositol is necessary for the growth of yeasts and other fungi, and in humans is especially abundant as part of a phospholipid found in the brain. Chemical formula:C6H12O6.